P56S mutation on VAPB MSP domain causes a familial ALS, characteristic of severe aggregation both in vivo and in vitro. We previously showed that P56S rendered the MSP domain to be predominantly disordered in water. Unexpectedly, here we reveal that P56S-MSP transforms into a highly helical conformation in a membrane environment. This chameleon transformation is shared by a splicing variant VAPB-3 with a truncated MSP domain, which is also highly disordered and buffer insoluble as demonstrated… CONTINUE READING